1. Field of the Invention
The present invention relates to an inkjet printer, and more particularly to an inkjet printer having an ink drying apparatus which has a simple structure and can effectively dry ink on paper.
2. Description of the Related Art
An inkjet printer is increasingly in demand in the market because it is generally quiet and able to print at a high resolution and print a color image at a low cost. Such an inkjet printer prints a desired image by spraying ink on paper through nozzles of a print head.
FIGS. 1 and 2 are sectional views schematically showing a conventional inkjet printer. Referring to FIGS. 1 and 2, a conventional inkjet printer will be described below.
In a conventional inkjet printer 10 as shown in FIG. 1, paper P stacked in a paper feed cassette 1 is picked up sheet by sheet by a pickup roller 2. The picked up paper P is fed towards a print head 6 along a paper guide 3 by a feed roller assembly 4 which includes feed rollers 4a and 4b. A desired image is formed on the paper P as ink is sprayed from the print head 6 into which an ink cartridge 5 has been loaded. The paper P with the image formed thereon is discharged outside a printer 10 by a discharge roller assembly 7 which includes discharge rollers 7a and 7b. 
During the printing process of the inkjet printer 10, the paper P gets wet by ink sprayed from the print head 6. In order to prevent the wet paper P from being distorted and ink from spreading on the paper P, the paper is dried after printing.
The inkjet printer 10 shown in FIG. 1 allows ink to naturally dry. However, such a natural dry method is not suitable for an inkjet printer which is developed to run faster by an advanced printer technology.
Since printing speed heavily depends on the speed of ink drying on paper, one cannot expect an increase in printing speed while insuring that the next paper sheet is not affected by the ink that has been sprayed on the current paper sheet. Accordingly, the natural dry method is not suitable for high speed printing and causes print quality degradation. In addition, since the sprayed ink is dried naturally and thus takes too long to dry, the paper tends to become distorted during the drying process.
In order to solve the above-mentioned problem, a means for drying ink such as a heater roller 8 has disposed between the discharge roller assembly 7 and the print head 6 of the inkjet printer 10 as shown in FIG. 2. Hence, this type of inkjet printer 20 dries ink by warming the bottom of the paper P through the use of the heater roller 8.
Accordingly, as the paper P passes the heater roller 8, the ink sprayed on the paper P from the print head 6 is dried, and high printing quality can be obtained even in case of high speed printing. In addition, since the sprayed ink is quickly dried, printing quality can be improved even more and the paper P can be prevented from being distorted.
However, because such an inkjet printer 20 requires the separate discharge rollers 7a and 7b and the heater roller 8, manufacturing costs increase.
In addition, considering a trend demanding a fast and compact printer, these two extra members increase the overall size of the printer, which is undesirable.